The James Webb Space Telescope can look deeper into space than any previous instrument. Researchers around the world hope the data it delivers will provide new insights into the origins of the Universe. The first images it sent back to Earth inspire dreams – not only among scientists.

By Jan Voelkel

There is something mystical and mythical about looking up into the sheer endless depths of space. If you think about what is sparkling in the firmament, you can hardly avoid asking the big questions. How did all of this develop? Where do we come from? Is there anybody else out there?

On the one hand, you can feel quite small in the face of the dimensions of the Universe – a tiny speck of dust on a tiny blue planet. On the other hand, the starry sky makes you realize how extraordinary our Earth and life are. Around us great darkness, everything seems quiet. But every now and then shooting stars pass by and remind us that something is happening in the sky. Because in fact, everything is moving and evolving. An unparalleled scientific mission was launched this year to explore these cosmic dynamics and find new answers to unexplained astronomical questions: the James Webb Space Telescope is without doubt the largest and most advanced instrument ever sent into space – by far.

New view of the young universe

The telescope took up operations in July 2022 at a distance of about 1.5 million kilometres from Earth. The very first images provided the deepest and most detailed views of space ever seen. It is a glimpse into the past, into the times of the first stars and galaxies more than 13 billion years ago. One innovation of the James Webb Telescope is the detection of infrared light.

James Webb - James Webb became head of NASA in 1961 under President John F. Kennedy. In his eight years at the helm of the US aerospace agency, Webb advanced many scientific missions to explore the planetary system, including the famous Apollo moon landing.

“This makes it possible, on the one hand, to look particularly deep into space and to look particularly far back in time,” said Dr Markus Röllig from the Institute for Astrophysics. The further one looks out into space, the longer the light has travelled – and the older it is.

At the same time, the Universe has been expanding since the Big Bang, which changes the wavelength of light. The light gets redder and redder the longer it travels, reaching the infrared range. On the other hand, the telescope’s infrared detectors can look into or through gas clouds. Since clouds do not block the view, scientists can now observe and study specific areas more precisely.

“With the help of the James Webb Space Telescope, one can suddenly investigate questions that were previously unanswered,” explained Dr Röllig. He and his colleague Dr Yoko Okada were among the scientists who, as members of an international research team, were allocated one of the coveted observation periods within the first three months of telescope operation. Röllig is convinced that “the telescope will lead to fundamental progress”.

Sunshields in the size of a tennis court

The launch was preceded by complications and delays. In the end, the telescope cost around 10 billion dollars, compared to the 3.5 billion dollars initially planned. Thomas Zurbuchen, NASA’s Associate Administrator for the Science Mission Directorate and thus master of the budget, said that James Webb represents the limits of what is possible and that it took several miracles to realize the project. That is not least because of its impressive dimensions – in fact, it is far too big. The space telescope consists of a 6.5-meter mirror segment made of 18 hexagonal-shaped segments. This makes the surface about seven times larger than that of its predecessor, the famous Hubble Space Telescope.

To protect the mirror and instruments from radiation and heat, they are shielded by five sunshields, each the size of a tennis court. But there’s a problem: There is no rocket big enough to transport the entire telescope. Therefore, the whole structure had to be foldable, unfolding only in space, which confronted NASA engineers with enormous challenges. In addition, the telescope has completely new measuring instruments and detectors that can not only probe back to the early days of the Universe, but also record what is happening right on our doorstep.

This is what makes the James Webb Space Telescope so interesting for Yokada and Röllig, because they are not investigating the endless depths of the Universe, but also our neighbourhood – in astronomical terms. The two are studying the region around the Orion Nebula – a cloud of gas and dust in the constellation of Orion that is only 1,350 light-years from Earth.

“The cloud is the remnant of a much larger cloud from which stars formed not so long ago – about one or two million years ago. This is no more than a blink of an eye in cosmic time dimensions,” Yokada said. “So we are looking at a nursery of stars.” Such areas are statistically quite rare. In addition, there are four very massive stars in the centre of the Orion Nebula that illuminate it like a floodlight. This makes the Orion Nebula an interesting object for astrophysicists to observe.

Layers of gas and dust resembling a puff pastry

In the Orion Nebula, new stars form from dust and gas, which in turn interact with the material around them. The scientists are investigating, for example, how fast and at what pace stars evolve, how much material they require and how the stars influence the surrounding material.

Looking into the Nebula and the ‘Orion Bar’ – so called because of its bar-like shape – is like looking into a bathtub from above, with its rim illuminated from the inside. “Therefore, it seems as if we are looking at a long column of illuminated gas. This formation is a significant advantage for us because we can work very well with our models,” Röllig explained. “You can say the Orion Bar is parallel, one straight layer, and everything shines intensively.”

The telescope’s large mirror and instruments allow scientists to study it with very high spatial resolution. It reveals a detailed layering of the Nebula resembling a puff pastry, showing with unprecedented precision where radiation is emerging or being depleted and where certain molecules occur. The observed carbon, hydrogen or nitrogen molecules are in turn associated with specific processes.

“We can examine in detail, like using a microscope, what exactly happens to the dust and which physical and chemical processes take place,” Yokada added. This has not been possible before in the exploration of star formation.

The new opportunities are generating great vigour and momentum in the scientific community. Scientists eagerly await new data that will lead to the next big discovery. In one of the earliest publications, a research team detected carbon dioxide in the atmosphere of an exoplanet 700 light-years away. In this case, that does not mean extraterrestrial life has been found, because the planet does not qualify for it. “But it is spectacular in any case,” said Röllig. “We will be able to watch planets form or analyse exoplanets for biomarkers in a new way. Data from James Webb could provide new insights into the formation of the Universe, galaxies, planets, or dark matter.”

Many researchers are sure that the data generated by the James Webb Telescope is very likely to be awarded a Nobel Prize. If, for example, it opens up new perspectives on the mysterious dark matter or the Universe directly after the Big Bang. The really big questions of our existence will probably remain unanswered. But the telescope can certainly shed some light on the great darkness around us.